Control apparatus



` Feb. 6, 1.951

R. R. STEVENS` CONTROL APPARATUS Filed Aug. 30, 1945 torn xc90 @Smau INI/ENTOR .Q03 l?. Szeven@ 535 (zam /1 TTORN EY Patented Feb. 6, 19,51

CONTROL APPARATUS Roy R. Stevens, Forest Hills, Pal., assignorto The WestinghouseAir Brake- Company,

Wilmerding,

Pa., a corporation of PennsylvaniaV Application August 30, 1945, Serial No. 613,628

13 Claims.

This-invention relates to controllapparatus and moreparticularly toapparatus arrangedv to controlv aplurality of operations in adesired sequence, such, for example, as operations incident to the control of a reversible prime mover.

In'my-Patent 2,482,301 of September 20, 1949,

there is disclosed anapparatus of the above type; forcontrollingftheoperation of a reversible Biesel engine. This apparatus embodies an opera-tors maneuvering cont-roldevice for4` controlling the starting, stopping-and reversingof the engine and an operator-s speedY control device arranged toV controla speed governor vfor regulating the supply` of fuel tothe engine. Structure controlled and=adjustableby the maneuvering' control device is also provided to limit tov any preselected degree the maximum amount of fuel thatV can be supplied tothe engine by-operation ofthe speed control device. 'lf-hepurpose of this fuel limitingV structure is to prevent the engine governor from operating to increase the supply of fuel to the engine to a degree exceeding that selected by the maneuvering control device in case the load on the` engineisincreased to an excessive or abnormal degreeor in other words, the limitingl structure-prevents undue straining of the engine underfsucha condition.

One-object of the invention is the provision of an improved-`V` control apparatus of the above generaltypa A more specic object of the invention is the provision ofla control'apparatus of the above general type embodying in the operators speedcontrol device, and therefore independent of the operator's maneuvering control device, control of the fuel limiting means for the purpose above set forth.

Other objects and advantages will be apparent fromy the following more detailed description of the invention.

In the accompanying drawing; Fig. 1 is a diagrammatic view, partly in section and partly in outline, of an apparatus for controlling the operation of a reversible prime mover, such as a Diesel engine and embodying one form of the invention; Fig. 2 is a sectional View of a directional;

control device shown in side;v elevation in Eig. l and taken on the line 2-2 therein; andFig. 3 is a sectional view of another embodiment of the invention.

Except as hereinafter pointed out the apparatus` shown. in the drawing :may be substantially like that disclosed' in-theaforementioned pending application.

Description Figs. 1` and 2` As shown in-the dawing, the reference-numeral I indicates an enginecrank shaft andthe reference numeral 2' indicates aengine. cam shaft 2 is shiftable longitudinally to dinerent positions which determine the direction ofA operation of theengine, andsaid-cam-shaft may therefore have what may be calledv an-astern position, in which it is shown in the drawing, and

may beshiftable'fromthis position inv thedirection of the right hand to an ahead position. As above used, the term astern indicates operation of the engine in one direction and the-term ahead indicates operation of the engine in 'the opposite direct-ion, merely for illustration and are to be considered synonymous with saidv one and opposite directions.

The reference numeral 3 indicates a fuel control shaft for the engine. 3 may have afuel cut-off position, such as indicated by adot and dash lineli, and maybe rockable out of said position in a counter-clockwise direction, as viewed inY the drawing, through a fuel controly zone for increasingfuel to` the engine. A dot and dash line 5 indicates a position which thefuel control sha-ft- 3 may assume tofuel to the engine, while a dot andY dash lineV 5A between the dot a position which said shaft mayassumev to pro- Vide fuel to the engine in an amount to obtain idling operation of saidengine.

The numeral 6 indicates a maneuvering control shaft for the engine. An operating lever 'l' secured to oneA end of shaft 6 for turning'same is disposed behind an escutcheon plate 8,- and is` operatively connected to an operating knob 9 in front of said plate. for the operator to grasp to operate leverl to tu-rn the shaft 6. The lever 'l has a` which it is shown in` the drawing,l and is movable from this position either in a countercloclcwise direction toward the legend Astern on plate 8, or in the opposite direction toward the legend Ahead on said plate. side of stop positionthe lever l' has Shift," Run and Start positions arranged in, the order named with the shift position adjacent the stop position, while corresponding but ifeversely arranged positions are provided at the opposite-or ahead side of stop position. Movementof lever l to any one of these different pocamshaft for said The engineis of the type in wl'iich-the and these terms are employed The fuel controlshaftprovide a maximum amount; of

and dash lines fil-and -'indicates- The knob 9` is provided' lstopl position in At the astern Y It.

sitions will correspondingly position the maneuvering shaft 5.

The reference numeral i l indicates a reversing motor for moving the engine cam shaft 2 to its different positions, while the reference numeral i2 indicates a control valve mechanism arranged for control by the maneuvering shaft 6 for controlling operation of said motor.

The reversing motor i comprises a casing containing a piston I3 having a piston rod I4 extending through the casing in coaxial relation with and having its end connected to the cam shaft 2 whereby reciprocation of said piston will move said cam shaft'longitudinally.y At one side of piston |3 is a pressure chamberf|5 connected to a control pipe I6, while at the opposite side of said piston is a pressure chamber I1 connected to a control pipe |53. When fluid under pressure K is supplied to pipe l at a time when chamber i1 is open to atmosphere by way of pipe I8, piston i3 willbemoved to the position in which it is shown in the drawing for moving the cam shaft 2 to its astern position to provide for operation of the engine in the astern direction. On the other hand, when pipe I5 and thereby pressure chamber l5 are open to atmosphere under p-ressure 1s supplied through pipe I8 to pressure chamber |1 the piston I3 will be moved tothe opposite or right hand end of its cylinder to thereby move the cam shaft 2 to its ahead position.

The control valve mechanism I2 comprises an astern valve device 23 for controlling the supply and release of fluid under pressure to and from pipe I6 and an ahead valve device 2| for controlling the supply and release of iiuid under pressure to and from the pipe I8. The ahead and astern valve devices 2o and 2| are identical in structure, each comprising a supply valve 22 contained in a chamber 23, which chamber is common to the two valves and is adapted to be constantly supplied with fluid under pressure from any suitable source by way of a pipe 24. Each of the valves 22 is arranged to control flow of fluid under pressure from chamber 23 to a chamber 25 and is provided with a stem 26 extending through the latter chamber and thro-ugh a bore in the casing into a chamber 21 which is open to atmosphere by way of a port 28. Chamber 25 in the ahead valve device 2| is connected to pipe I8 while chamber 25 in the astern valve device 20 is connected to pipe i6. Each valve stem 26 is provided with an axial bore 29 open at one end to chamber 25 and open at the opposite end through the end of said stem to chamber 21. A plunger 32 slidably mounted in a bore in the casing extends into chamber 21 in coaxial relation `with the adjacent end of each valve stem 26, and

oneI end of said plunger constitutes a valve arranged to cooperate with a seat on the end 0f Vsaid stem for closing communication between bore 23 and chamber 21. A spring 33 contained inchamber 23 acts on each supply valve 22 for urging it to its closed position.

Two identical but reversely arranged cams 3| and 32 are mounted on the maneuvering shaft E for cooperation with the two plungers 30 to con-V troloperation of the ahead and astern valve devices 2Iand 2), respectively. With the operators control lever 1 in the astern shift position the cam 32 is adapted to seat plunger 3B in the astern valve device 2@ against the end of the respective supply valve stem 25 and to open the v respective supply valve 22 for supplying fluid under pressure topipe I5, while in all other posiand fluidV v 1 to the ahead shift tions of said lever said cam is adapted to permit closing of said valve by the respective spring 33 and to also permit movement of the respective plunger 33 to the position shown in the drawing for releasing uid under pressure from chamber and pipe I6 through bore 29 in the respective supply valve stem 26 to chamber 21 and thence to atmosphere. is adapted to operate the ahead valve device 2| upon movement of the operators control lever position to supply fluid under pressure to pipe i8 and in all other positions of said lever to open said pipe to atmosphere. l v

It willthus be apparent that when the operators controly lever 1 is moved to the astern shift position the control valve device |2 will operate to supply fluid under pressure to chamber l5 to effect operation of the reversing motor to move the cam shaft 2 to its astern position to provide for operation of the engine in the one direction, but movement beyond this shift position to the astern run and start positions will cause operation of the control valve mechanism l2 to release fluid under pressure from said piston chamber. Likewise, if the operators control lever 1., is moved to the ahead shift position the control valve mechanism I2 will be operated to supply iiuid under pressure to chamber I1 inthe reversing motor to effect operation of said motor to move the engine cam shaft 2V chamber l1. It will thus be seen that since fluid under pressure is released from chambers I5 and I1 wherrlever 1 is out of the shift positions it is necessary for the operator in reversingltheV direction of operation of the engine to allow said lever 1 to remain in the astern shift position or in the ahead shift position for a period of time sucient for the reversing motor i I to propv erly position the cam shaft 2.

Fluid under pressure is released from pressure chamber l5 or |-1 in the reversing motor II after Y said motor has operated to properly position the cam shaft 2, asv above described, in order to remove thrust on the connection between the reversing piston I3 and the cam shaft 2.

TheV reference numeral 35 indicates an engine starting air valve device which is-operative to supply engine starting air from a supply pipe 36 to a Vpipe 31 which is adapted to conduct such l starting air to the starting mechanism (not shown) of the engine for starting the engine to turn in a direction determined by the position of the cam shaft 2.

The starting air valve device 35 comprises a casing having a chamber 34 connected to the supply pipe 36 and containing a valve 38 arranged 'to control flow of starting air from said cham- The valve 38 has a fluted stem Y 39 engaging a like stem on an oppositely seating e ber to pipe 31.

valve 4|! contained in a chamber 4| which is open to atmosphere through a port 42. The valve 4|] is arranged to. control communication between pipe Stand the atmospheric port 42. A` spring 43 in chamber 34 acts on the supply valve 38 for urging it to its seated position andl for opening the valve 4U. A stem [i4 projecting from valve di@ through chamber 4| and a bore in the casing is provided for closing valve t() and for opening valve 32 against the opposing force of spring 43.

A cam i5 secured to the maneuvering shaft I` li for operation thereby is arranged to operate stem In a like manner the cam 3| y Vbe supplied to 5, M'to close valve 4B? and open valve 38 in the two "start positions of the operators control lever 1 and to permit closure oi' valve 38 and opening of valve 40 by spring 43 in all other positions oi' said lever. It will thus be seen that when the operators control lever 1 is moved to either of the two "start positions engine starting air will pipe 31 to effect starting of the engine, while in all other positions of said lever pipe 31 will be open to the atmosphere.

The reference numeral 41 indicates a power means in the form of a fluid motor adapted to be controlled by an operators control device which may belocated at a remote station ii desired, for effecting movement by power of the maneuvering shaft 6- to its diierent positions.

Thepower means 41 and operators control device 48 may be generally similar to devices fully disclosed in Patent No. 2,379,306 issued to Arthur G. Larson and Cecil S. Kelley on June 26, 1945, and since reference may be made to this pat ent the following description of said power means and operators control device `will be limited to only such detail as is deemed necessary to a olea understanding of the present invention.

Briefly, the power means 41 is arranged to be operated by iiuid under pressure supplied to either an ahead pipe 55 or to an astern pipe 51 to turn the maneuvering shaft 5 in, respectively, either the ahead direction or in the astern direction, through the medium of a sprocket wheel 52 associated with the motor, a sprocket wheel cured to the maneuvering shaft 6 and a connecting driving chain 54. The motor [i1 is adapted to assume different positions corresponding to diiferent pressures of fluid in either the ahead pipe 5U or in the astern pipe 5l, so that by providing different selected pressures of fluid in the ahead pipe 5t, for instance, the maneuvering shaft 5 can be caused to turn to and stop in any selected position at the ahead side of stop position, while the provision of the same selected pressures of iiuid in the astern pipe 5l will cause the maneuvering shaft 6 to turn to and assume the corresponding positions at the astern side of stop position. When the same pressures of fluid are provided in both pipes 55 and 5|, the motor d1 will operate to move the maneuvering shaft 5 to its stop position.

The operators control device d8 which is provided to control the pressure of fluid in pipes and 5| comprises a lever 55 having a neutral or stop position and at one or the astern side thereof run and start versely arranged run and start positions, these positions, it will be noted, correspond in name and disposition to the diiTerent positions of the operators control lever 1 and the maneuvering shaft '6, with the exception that lever 55 has no shift positions for reasons which will be laterl brought out. The operators control device 1.18 is arranged` to control directly the supply and release of fluid under pressure to and from two pipes 5S and 51 which are adapted to be connected to pipes 5i) and 5i, respectively, by means to be later described. In stop position of lever 55, the operators control device 48 is adapted to provide in both pipes 55 and 51 iiuid at the same and at a minimum degree of pressure to cause operation of motor 41 to move the maneuvering shaft 5 to the corresponding or stop position. Movement of the operators control lever 55 to either the run or start position at the ahead positions, and at `the r opposite or ahead side of stop position residev of stop position is adapted to open the astern pipe 51 to atmosphere and to provide fluid in pipe 56 at pressures operation or motor 41 shaft 5 to the position to move the maneuvering corresponding to that of said lever. Movement of the operators control lever 55 to the run and start" position at the astern side of stop position will open pipe 56 to atmosphere and supply fluid to pipe 51 at a pressure corresponding to the position of said lever to thereby eiect operation of motor 41 to correspondingly position the maneuvering shaft In other words, when the operators control lever 55 is moved to any selected position the uid motor 41 will act to move the maneuvering shaft `5 to the corresponding position.

Interposed in the communication between pipes 55 and 55, and pipes 51 and 5| are two pressure limiting valve devices 59 and 60, respectively, and an interlock valve device 5 i.

Each of the pressure limiting valve devices 55 and 55 comprises a casing having a chamber 52 containing a valve 53 arranged to control flow of uid under pressure from said chamber to a chamber (ill. A spring 55 in chamber 52 acts on valve 53 for urging it to its seat. The valve 55 has a stem 55 extending into chamber 55 wherein it engages one side of a exible diaphragm 51 which forms one side of chamber At the opposite side of diaphragm 51 is a chamber it? which is open to atmosphere through a passage i551, and which contains a spring 15 acting on the diaphragm in a direction to unseat the valve The pressure of spring 15 on diaphragm 61 is such as to permit deflection of said diaphragm and closing of valve 63 by spring 55 when the pressure of fluid in chamber 5t is increased to a certain chosen degree, for reasons which will be later brought out. In the pressure limiting valve device 55 chamber 62 is connected to pipe 55 and chamber 54 is connected to pipe while in the limiting valve device 55 the corresponding chambers are connected, respectively to pipes 51 and 5l.

The pipes 55, 51, 55 and 5l all lead to the interlock valve device 5i which may comprise a rotary valve 12 having two different operatingpositions and which is arranged to be moved to said positions by a lever 13; The lever 13 is operatively connected to a rod 14 which has a lost motion connection with a rod 15 through the medium of an arm 16 on rod 15 and spaced collars 11, 18 on rod 14. The rod 15 is connected to the reversing piston i3 at the side oppcsite the piston rod I4.

When the reversing piston I3V is in its astern position in which it is shown in the drawing, engagement between arm 15 on rod 15 and collar'11 on rod 15 will position the rotary valve 12 inwhat may be called an astern position in which it also is shown in the drawing. When, hcweven'the reversing piston I3 is moved to its ahead position at the opposite or right-hand end of the cylinder, the arm 16 will engage collar 18 on rod 15 just before the piston attains said position in order to actuate lever 13 to turn rotary valve 12 to its other position, which may be called an ahead position, and in which said lever will occupy a position suchas indicated by a line 19. It will be apparent that movement of piston i3 from its ahead position to its astern position will turn the rotary valve 12 to the position in which it is shown in the drawing.

The rotary valve` 12 is provided with two cavities and 8i, the cavity 8i) being adapted to such as required to effect establish communication between pipes 51 and l in the astern position of said valve, while the cavity Si is adapted to establishv communication between pipes 55 and 50 in the ahead position of said valve. When communication is es tablished between pipes 5l and 5| the communication between pipes 5E and 55 will be broken, and vice versa. i

In operation, if the operator moves the control lever 55 from stop position to the ahead start position to supply fluid to pipe 56 at the pressure required for operating motor 4l to turn the maneuvering control shaft 5 to its ahead start position, iiuid will flow from pipe 155 to chamber 52 in the pressure limiting valve device 59 and thence past the respective open valve 63 to pipe 5i! leading to the motor 4l, it being noted that communication between pipes 55 and 55 through the interlock valvepdevice 6l is closed at this time. When the pressure of' fluid thus supplied past valve E3 in limiting valve device 59 and acting on the respective diaphragm 5l is increased to a degree suiiicient to overcome the opposing force of spring 15, said diaphragm will deflect against said spring to permit closure of valve 53 to thereby limit the pressure of fluid obtained in pipe 5S to a degree determined by the pressure of said spring. The pressure of spring 'lil in the limiting valve device 5S is such as to limit the pressure of uid thus provided through pipe 5&3 in the reversing motor l? to a degree which will cause operation of said motor to turn the maneuvering control shaft 5 only to the ahead shift position.

Operation of the motor il to turn the maneuvering controi shaft 6 to its ahead shift position will effect operation of the control valve mechanism i2 and thereby of the reversing motor i l to move the cam shaft 2 from its astern position, in which it is shown in the drawing, to its ahead position. When the cam shaft 2 attains its ahead position the interlock valve device 5l will have been operated by the reversing piston i3 to establish communication between pipes 56 and 55 by way of cavity'l in said valve device, so

that fluid at the pressure provided in pipe 55 by the operators control valve device 48 with lever 55 in its ahead start position will then become effective through pipe 55 in motor 51 and cause operation of said motor to turn the maneuvering shaft 5 to its ahead start position, for thereby operating the starting air valve device 35 to supply starting air to pipe 31 to effect starting of the engine to turn in the direction determined by the position of the operators control lever 55 andY thereby of the cam shaft 2. After fuel is supplied to the engine, in a manner which will be later described, and the engine fires and is running on fuel the operator will then movelever 55 from the ahead start position to the adjacent run position to thereby cause operation of motor @l to turn the maneuvering control shaft 5 to the corresponding run position for effecting operation of the starting air valve device 35 to cut off the supply of starting air to the starting air pipe 5l. While the engine is running the operators control lever 55 will then be left in the run position.

On the other hand, if the operator desires to operate the engine in the astern direction he will move lever 55 to the astern start position to thereby cause operation of motorV 4l to first move the maneuvering control shaft 6 lto its astern shift position, as limited by operat operation tion ofthe limiting valve device 60, and then to the astern start position upon operation of the interlock valve device 6l. In thefastern start position of the maneuvering shaft 5 the starting valve device 35 will be operated to supply starting air through pipe 3l to the engine, and after the engine fires and is running on fuel the operator will return lever 55 to its astern run position in which it will then remain during operation of the engine in the astern directicn.

It will now be seen that uponmovement of the operators control lever 55 to either of its start positions the limiting valve device 59 or 5G acts to limit operation of the fluid motor 4l to prevent turning of the maneuvering control shaft 5 to the corresponding start position to effect starting of the engine, until after the cam shaft 2 has been positioned according to the operation of said lever, but immediately upon proper positioning of the cam shaft, the motor M operates to cause operation of starting air valve device 35 to effect starting of the engine. After the engine is started the operator moves the control lever 55 back to the adjacent run position in which it is then allowed to remain during operation of the engine in the selected direction.

The structure will operate in the manner just described in starting the engine fromistop in either one direction or in the opposite direction,

or in quickly reversing the engine from opera--v tion in one direction'to operation in the opposite direction, it being noted that in reversing. the enginerfrom ahead to astern, for example' the ahead pipe 55 will be vented at the same time as fluid is supplied to the astern pipe 5l, so

that the motor el will promptly move the maneuvering control shaft E in accordance with the of lever 55 and as governed by the limiting valve device 59 or 6i! device 5i. The Structure will also operate in the same manner in case the operator moves lever 55 from the astern run position to the Y ahead start position to start and operate the engine in the ahead direction. It is merely desired to point out, however, that in quickly reversing the direction of engine operation, the

cam shaft 2 may be operated to condition the engine for operation in the newly selected direction before the engine comes to a stop from operation in the opposite direction, in which' case the starting air supplied by the starting air valve device 35 to the engine will initially act in the engine as a brake, in the usual well knownmanner, to promptly bring the engine to a stop and will then be immediately effective to start the engine turning in the new direction, as determined by the position of the cam shaft 2.

Connected to one end of the fuel control shaft 3 is one end of a lever 82 having in its opposite end a roller swhich is adapted to engage the peripheral surface of a fuel cut-off cam 84 on the A maneuvering shaft 6 which cam is different from a similar cam disclosed in the aforementionedV pending application. When the shaft 5 is in stop position, the cam 84 is adapted to actuate lever 82 to move the fuel control shaft 3 to its fuel out-off position indicated by the dot and dash line il. The cam 84 is so designed, however, that when the maneuvering shaft 5 is in any position out of stop position, the lever 82 and fuel control shaft 3 are free to move, with respect to the maneuvering control shaft 6, from the fuel cut-off position indicated by the dot and and interlock valve dash line 4 to any position up to and including the maximum fuel supply position indicated by the dot .and dash line 5. It will thus be seen that the only control of engine fuel by the operators control valve device 4B is that for cutting olf fuel upon movement of lever 55 to stop position in order to eiect stopping of the engine.

vAlso operatively connected to the fuel control shaft 3 is one end of a fuel control lever fit the opposite end of which is connected by a link il toone end of a lever B3. The lever dt is pivoted intermediate its ends on a fixed fulcrum pin 89 and the opposite end of said lever is operatively connected to aplunger 90 of a speed governor el.

The speed governor 91 may, for the purpose of illustration, comprise a head 9| in which the plunger 9S is slidably mounted. Two centrifu.. gal governor arms 92 are pivoted on pins 93 in the head 9| and are operatively connected to a collar 94 secured to plunger 99. The head u! is operatively connected by gears 55, Sil to any suitable rotatable part of the engine such as the crank shaft I. Upon an increase in speed of the crankshaft I the governor arms 92 will act through collar 94, plunger 9e, lever 88,.1inl 8l' and lever 8:3 to move the fuel control shaft 3 in the direction of the fuel cut-olf position indicated by the dot and dash line 4, while movement of lever 88 in the opposite direction against the opposing actionlof the governor arms 32 will actuate lever Se to move the fuel control shaft 3 in the opposite directionor out of the fuel cutoi position for yincreasing the supply of fuel to the engine.

The governor 91 further comprises a control spring Sii having one end connected to lever 88 between the fulcrum pin 8S and the link 87 and is provided to oppose the action of centrifugal `force on the governor arms 532. The opposite end of spring 93 isconnected to one end ofa rod 953 of `a governor control motor IDD which is operative to adjust the force of said spring on said lever.

The motor Illu-comprises a `cylinder lill, `containing a piston H32 to which the rod 9S is operatively connected. vAt one side of piston |132 is a control chamber `ISS connected to a control pipe IM, while at the opposite of said piston is a nonpressure Achamber It which is open to atmosphereithrough a passage |06 and which contains a control spring |91 acting on piston H32 in opposition to pressure of fluid in chamber |83.

The .pipe Ilii is adapted to be connected through an interlocl; valve device M8, constituting a part of the invention, toa pipe Iilllci leading to an operators fuel or speed control valve device IGS which is provided for controlling the Vpressure of fluid in chamber I 33 of the governor control motor Iild. The speed control device ||l9 may be of any suitable type which will vary the pressure of fluid in chamber lila in proportion to the extent of movement of a control lever II l? out of an engine idle position, in which it is shown in the drawing, and in which a minimum of pressure of fluid, such as ten pounds per square inch, will be provided in pipe IMA. A maximum pressure of i'iuid will be obtained in pipe i-'i-A with lever Ilii moved to a position designated in the drawing by the legend Full speed. Any desired pressure between the maximum and minimum pressures may be provided in pipe itl/A by suitable adjustment of lever H0 between its idle and "full speed positions.

"The interlock; valve device i E38 comprises a casing having a chamber il open to pipe IMA, and

another chamber II2 open 'to pipe ltd. A double seating valve H3 contained in chamber H2 is arranged to control communication between said chamber and the chamber HI at one side of the valve and a chamber lid at the opposite side. A. spring I i5 in chamber Iii acts on the valve |53 for moving it to the position in which it is shown in the drawing, in which position communication is opened between chambers ill and ii2 and thereby between pipes iji and idd, while chamber H2 and pipe Il are disconnected from chamber Hd which is open to atmosphere through `a port lili. Chamber lie is formed at one side of a piston ill which is operatively connected to valve I i3. At the opposite side of piston |i'i is a chamber H8 pipe H9.

Associated with the fuel control shaft 3 and preferably with the adjusting lever B5 is a maximum fuel limiting device which is preferably in the form of a huid pressure adjustable stop |2i constituting another part of the invention. This device comprises a cylinder I2! containing a piston 22 having a rod |23 projecting from one face and arranged to engage or to be contacted by the fuel control lever et. At one side of piston |22 is a pressure chamber |253 open to pipe Iill while at the opposite side is a non-pressure chamber |25 which is open to atmosphere through a port i25. A spring |27 in chamber |25 acts on piston |22 in opposition to pressure of fluid in chamber |24.

It will be noted that pipe IM is connected to pressure chamber |93 in the governor control motor Iiiii and also to pressure chamber lilll in the maximum fuel limiting device IZi, whereby, in accordance with the invention, the pressure of fluid in both of these chambers is adapted to he controlled in unison by operation of the operators speed control device VliEi when pipe I d4 is connected to pipe IMA, while both of these chambers are adapted to be opened to atmosphere together when valve H3 in the interlock valve device |233 is moved to the position to close the communication between chambers i I2 and II and to open chamber i i2 to the atmospheric chamber Iifi. The control of the interlock Valve device Idil will be hereinafter described.

Inthegovernor control motor Iil the pressure of spring I lll on 4piston H92 is such, according to the invention, as to prevent movement of said piston out of the normal position in which it is shown in the drawing against the minimum. pressure (l0 pounds) of fluid provided by the operators speed'control device IUS with the lever III] thereof in its idle position, but to permit movement of said piston against said spring a distance in proportion to the increase in pressure in said chamber in excess of l0 pounds as the operators speed control lever ilu is moved out of idle position in the direction of full speed position.

In the minimum fuel limiting device IZil the pressure of .spring |23? on piston |22 is such that when the minimum pressure of fluid is effective in chamber i213 the piston |92 and rod E23 will be vmoved against spring |27 to a position which will allow movement of the fuel control lever i3d by spring Se out of the fuel cut-olf position to a position slightly above the engine idle position idicated by the dot and dash line 5a. When the pressure of fluid in chamber 32e is then increased above the minimum value of l0 pounds the piston 22 will move in unison with the governor control piston I 62, and the rod |23 will remain out of Contact with the lever S6 except under a condiwhich is open to a control tion tobe later described. When pipe |04 is open to atmosphere by way of the interlock device |88, 'springv |21 in the maximum fuel limiting device |22 is adapted to operate piston |22 and thereby rod |23 to move the fuel control lever 86 toits fuel cut-off position indicated by the dot dash line 4.

Let it be assumed that the parts of the interlock valve device |88 are in the position shown in the drawing opening communication between pipes |04 and IMA, and that the operators speed control lever IIE] is in idle position and that piston |22 and rod |23 in the maximum fuel limiting device are moved to the position to permit movement lof the fuel control lever 86 and shaft 3 by spring 98 to a position slightly above theV engine idling position indicated by the dot and dash line 5a. Let it further be assumed that in response to operation of the operators maneuvering control valve device A8 the starting air valve device 35 has been operated to supply starting air to the engine and that the engine is turning under the inuence of such air in the direction determined by the position of the cam shaft 2. With the fuel control lever 3B positioned to supply fuel to the engine the engine will fire upon being placed in motion by the starting air and will then run on fuel following which lever 55 of the maneuvering control device i3 will be moved from whichever start position it may be in to the adjacent run position to thereby effect operation of the starting air valve device 35 to cut-olf the supply of starting air to the engine. The engine will then continue to run on fuel.

As soon as the engine starts to operate as just described the speed governor 9'! will act to rock lever 8B against spring BB and thus pull the fuel control shaft 3 in a clockwise direction to reduce the amount of fuel supplied to the engine, and this action will continue until a balance is obtained between the centrifugal force of the governor arms 92 and the pressure of spring 98, at which time the fuel control lever 8B will assume its engine idling position, indicated by dot and dash line 5a, so that the supply of fuel to the engine will be such as'to allow operation of the engine at idling speed.

If the operator now desires to increase the speed or power output of the engine he will move lever Ill] away from idle position to thereby increase the pressure of fluid in pipe |64 to a degree corresponding to theposition of said lever. This pressure of fluid in pipe im effective in chamber |33 of the governor control motor lili) Aand in chamber 24 of a maximum fuel limiting device |20 will move the respective pistons H52 and |22 in unison. This movement of piston |22 will be without effect except to maintain the rod |23 vout of contact with the fuel control lever 85, but the movement of piston |22 to a position corresponding to that of the operators speed control lever Il] will act to correspondingly increase the force of the governor control spring Q8 against lever 88. The lever 85 will thereby be operated to turn the fuel control shaft 3 in the direction of the maximum fuel position indicated by the dot and dash line 5 to increase the supply of fuel to the engine. The engine will then accelerate and cause operation of the speed governor 37 torock lever 38 against spring 98 and thus move the fuel control shaft 3 in the opposite direction 'to reduce the supply of fuel to the engine, and this action will continue until a` balance is obtained between the. lrllrual QKC@ of the governor arms 92 and the adjusted force of spring 98, whereby the supply of fuel to and thus the speed of the engine will be increased to a degree corresponding to the increase in pressure of fluid in the control pipe |04 and thus corresponding to the position of lever ||0` out of idle position.

On the other hand if `the engine is operating at a" certain speed and the operator desires to reduce the speed he will move lever IIE! back in the direction of idle position to thereby reduce the pressure of fluid in the control pipe |64 to allow movement in unison of the governor control piston |62 and of the maximum fuel limiting device piston |22 by their respective springs |91 and |2'i to a new position corresponding to the new position of lever H0. This movement of the governor control piston |62 willact to reduce the force of spring S8 on lever 88, and the speed governor 9'! will then operate to correspondingly change the position of the fuel control lever 35 and reduce the supply of fuel to the engine so that the engine will decelerate to a speed corresponding to the change in position of the operators control lever H3. It will thus be seen that by suitable adjustment of lever H0, any desired rate of fuel supply to and thus speed of the engine may be attained. f

During normal operation of the engine under control of the governor motor |00, as above described, the maximum fuel limiting device l2!! serves no useful purpose, since piston |22 moves in unison with piston |02 and maintains rod `|23 out of contact with the fuel control lever 8B, but it should be noted that the piston |22 and rod |23 always assume an adjusted position corresponding to that of the governor control piston |02 and therefore corresponding substantially to the amount of fuel which the operator desires to supply to the engine. The purpose of thus adjusting the maximum speed limiting device |20 in synchronism with the fuel governor motor |00 is to prevent the supply of fuel to the engine being increased substantially in excess of that chosen by adjustment of the operators fuel control lever ||0, in case of what y might be considered the application of an excessive or abnormal load to the engine, so as to thereby prevent undue straining of the engine under such a condition as will now be described in greater detail.

Let it be assumed that the engine is operating at a chosen speed corresponding to the preselected position of the operators speed control lever H0, under which condition piston |22 and rod |23 of the maximum fuel limiting device i2!) will be correspondingly adjusted, and an excessive or abnormal load is imposed upon the engine. Due to this abnormal load the engine will tend to slow down and reduce the centrifugal force of the governor weights 8-2 and thereby render spring 9B eective to rock lever 8B and move the fuel control lever 86 and shaft 3 in a direction to increase the supply of fuel to the engine so es to maintain the engine at the speed corresponding to the adjustment of the governor motor |00'. The slight distance which the fuel control lever 86 can thus be moved by the governor spring 98 is, however, limited by contact between said lever and the piston rod |23 which at this time acts as a stop to prevent further movement by the governor control spring V$38, so as to thereby limit the increase in fuel supply to the engine to a relatively small degree in excess of that preselected by the position of 'sealing rings 'leakage of fluid under pressure from chamber `connected, for movement in theispeedcontrol lever I0. .It willzthus beseen thatregardless of `the ,position of the operators control lever |||J between the idle and full speed positions, .the maximum fuel limiting device |20, being adjusted in accordance with `the position of said lever, will act to prevent Fany substantial increase in fuel supply `to the engine `over that preselected by the operator, in case of the sudden application of an excessive or abnormal load to the engine, whereby the engine will be prevented from working under a load substantially 'in excessof that selected Aby the adjustment of the control lever IIB.

Pipe 9 connected 'to piston chamber ||8 in the `interlock valve device |58 leads to a directional control device ISU, which comprises (Fig, '2) 'two poppet valves I3! and |32 contained in `chambers |33 and |34 which are open to the ahead and astern pipes or 50 and 5|, respectively. The poppet valves I3! and |32 are arranged side by side with parallel extending fluted stems |35 and |36, respectively, which extend into a chamber |31 to which is connected pipe ||9. The valves `|3| and |32 are provided to control communication between chambers |33 and |34, respectively, and chamber |31, and a spring |38 in each of the vchambers |33 and |34 acts on the respective valves |3| and |32 to urge them to their closed position.

The valve stems |35 and |35 engage, respectively, `two spaced operating plungers |39 and. |49 which are slidably mounted 'in the casing and-which are provided with stems lill and |42 Aextending to the exterior of the casing through |43 which are adapted to prevent |31 past the vrespective plungers and stems to atmosphere. Two rockable cams |44 and |45, -fulcrumed on pins |45 in the casing, are provided `for controlling the plungers 4| and `|42 respectively` These cams are of identical structure but are reversely arranged and each `is connected to the respective plunger 4| or |42 Ithrough the medium of a pressure transmitting element |41 which is rockably mounted on a pin |48 secured in the casing. Eachiof-the cams |44 and |45 is provided `with a surface |49 which, when in contact with the respective pressure transmitting element |41, will unseat the respective valve i3! or |32. face M9 each cam is provided with a recess |55! adapted to lreceive the respective element |11? to permit movement of `the respective plunger |39or |45 a spring |5| to a, position to permit closure Yof the respective respective spring |38.

The two cams |44 and |45 Yare operativeiv unison by a link |52 and since the `tioned. movement of the link and cams to the position in which they are shown inthe drawiing will 'effect 'opening of A'valve |3| and closure of valve |32, while movement of said link and camsin a counterclockwise direction as `viewed inthe drawing to aposition in which surface |49 on cam |45 engages the respective element |41 will eiiect opening of valve |32 and closing of valve |3|.

The directional control device |35 further comprises Ya control piston |54 and a piston rod |55 having one end connected to said piston and erztending through a non-pressure chamber |55 at `one side of said piston. At the opposite side of piston |54 is a pressure chamber |51 which listin `Adjacent the survalve tti or by the camsare reversed as above men i `l4 'constantcommunication through a'pipe |158 with the engine starting air pipe 31.

The opposite or outer end of piston rod is pivotally connected by a pin |59 to a lug l 6|! projecting from the back face of a friction shoe 5|. rlhe opposite face of shoe isconcave providing a surface |62 which is arranged to frictionally engage the peripheral surface of crankshaft Also connected to pin |59 is lone end of a link itthe opposite end of which is operatively connected to the'adjacent end of "a cam operating link |52.

rlhe pistonrod |55 is capable of side movement in the non-pressure-chamber |56 from the position in which it is shown in the drawing, and

which is defined by `contact with a surface |754 in the casing, to a position in which said rodengages a surface |65 in the casing. Adjacent the surface |55 the casing is provided with a pin |65, and the link l |33 has two receses |51, one of which is arranged to receive the pin its with thefpiston .rod |55 in the position in which it is shown in the drawing, while the other recess |61 is arranged to receive `pin |55 in the other position of said rod.

The piston rod |55 is encircled within chamber |55 by a spring |58 one end of which engages the piston |54 while the opposite end is supported on ashoulder i'in the casing. This spring is under pressure and adapted to move the piston |54 `to the position :in `which it is shown in the drawing when pressure chamber |51 is 4open to atmosphere. When fluid 'under pressure is supplied to pressure chamber |51,'in a manner which will later be described, the piston |54 is adapted to move against spring |53 to Ioperate rod |55 to move the friction shoe |6| into contact with thecrankshaft l. When the shoe It is in contact `with the crankshaft, the link |53 will be elevated to a position in which it will be disconnected from the pin |36, When fluid under pressure is released from chamber `l5? spring |68 .is adapted to actuate piston '|54 and rod |55 to move the shoe 5| out of contact with the crankshaft, under which condition pin |55 will enter either oneor `the two recesses icl, to secure the links `|53 and |52 and thereby cams |44 and |45 against accidental movement out of the selected position.

The interlock valve device I t8, as controlled by thedirectional control device i3d, is provided to render the maximum fuel limiting device |26 effective to actuate the fuel control shaft 3 to its fuel cut-oii position, when the operator actuates lever of the maneuvering `control device i3 to reverse the engine from one direction of operation to the opposite direction, until after the engine starts to turn in said opposite or the selected direction under the influence of starting air supplied through vpipe 31. More specically let it be assumed that the engine is operating in the astern direction with `the operators control lever 55 `in the "astern frun position, in which position pipes 57 and 5| will be ycharged with fluid under pressure, and the ahead pipes E55 and 5|) will be open to atmosphere. In the directional control device |35 valve |32 will be closed while valve iti will be open connecting pipe ||9 from the interlock valve device |53 to the vented ahead .pipe 5t for reasons which will later become apparent. With pipe ||9 thus vented the parts of the intericck valve device |98 will be in the positions in which they are shown in the drawing, establishing communication between pipes |14 and ,iia, whereby the operatorby operation of lever "i Il! may control l the governor motor mi) and thereby the amount of fuel being supplied to the engine.

With the engine operating in the `astern direction let it be assumed that the operator desires to reverse the direction of operation from astern to ahead, in as short time as possible. To accomplish this he will move lever 55 of the ma* neuveringcontrol device 48 fromthe Astern run position to the ahead start position to thereby open pipes 51 and 55 to atmosphere and at the same time to supply fluid under pressure tothe ahead pipe 56 and thence to pipe 5| to effect movement lof the cam shaft 2 to its ahead position, followed by operation of the starting air valve device 35 to supply starting air through ,Y pipe 31 to initiate starting of the engine. Fluid under pressure supplied to the ahead pipe 55 and to pipe 5t as just described will also flow to chamber |33 in the directional control device |35 and from said chamber |33 past the open valve |3| to chamber |31 and thence through pipe li!) to pressure chamber MB in the interlock valve device |98. The interlock valve device itil will thereby be operated upon initiating the reversal in direc- Y tion of engine operation to close communication between pipes la and |64 and to open the latter pipe and thereby chambers |55 andY |24 in the fuel control motor |50 and in the maximum fuel limiting device |2,'respectively, to atmosphere. The maximum fuel limiting device will then promptly operate, in response to operation of the maneuveringcontrol lever 55 to reverse the direction of engine operation, to move the fuel `control lever 86 to its fuel cut-onc posia tion to thereby cut off the supply of fuel to the engine so that the engine may be stopped under the influence of starting air as above mentioned, or by any other conventional means.

When the starting air valve device 35 is oper ated to supply starting air to the engine a .portion of this starting air will ow through pipe |58 to piston chamber H31 in the directional control device |3|i and therein act on piston |54 to force the friction shoe IBI into contact with the peripheral surface of the crankshaft VIf at the time starting air is supplied to the engine and the shoe IBI is moved into contact with the crankshaft the engine is still running in the direction of last operation, i. e., in the astern direction in the lpresent instance, the shoe it! and thereby the other parts of the directional control device |33 will remain in the position in which they are shown in Fig 2. However, as soon as the engine and the crankshaft starts turning inthe new, or the ahead direction after the interlock valve device |08, while the opening of valve |32 will connect said chamber to the astern pipe 5| which at this time is open to atmosphere through the operators maneuvering control device 48. Fluid under pressure will therefore be released from chamber Mil in the interlock device |98 just as soon as the engine starts to turn in the ahead direction and said device will then operate to reestablish communication between pipes IM and IMQ., whereby the pressure of fluid provided by the operators speed control device |09 chamber |24 in the maximum fuel limiting device i2@ and operate piston |22 to move rod |23 out of Contact with the fuel control lever 8E.' The fuel contro-l lever S5 will then be operated by the governor control spring 9S to a fuel supply position for supplying fuel to the engine. The engine will then fire and run on fuel.

As soon as the engine res and is running on fuel as just described, the operator will move the control lever 55 to the ahead run position to effect operation of the starting air valve devicei 35 to out onc the supply of starting air to the engine and to open pipe 3l to atmosphere by way of vport 42. Fluid under pressure will then be released from piston chamber |51 in the directional control device lii by way of pipe 31 to permit movement of shoe |G| by spring |63 out of contact with the crankshaft. With the engine now running on fuel the operator by suitable adjust-ment of lever il!! can vary the fuel supply to the engine, as desired.

If the operator operates the maneuvering controllever 55 to reverse the direction of operation of the engine from ahead to astern, the interlock valve device itil, as controlled by the directional controi device |3ii, will promptly operate to render the maximum fuel limiting device |20 effective to move the fuel control lever 8B to the fuel cut-off position in order to allow the engine kto stop, and then immediately upon starting of the engine in the opposite or chosen direction under the influence of starting air, said devices will operate to effect operation of the maximum fuel limiting device to permit supply of fuel to the engine under the control of the governor motor it, as will be apparent without further description.

Whenever the operator desires to stop the engine, regardless of the direction of operation, he need only move the 1maneuvering control lever 55 to sto-p position, to thereby cause operation of motor il to turn the maneuvering control shaft t to its stop position. This movement ,of the maneuveringV control shaft will operate cam 84 and thereby lever 82 to turn the fuelV control shaft 3 to and then hold it in its fuel cut-off position, as long as the operators control lever V55 is in stop position.

It will be noted that when the engine is stopped as just mentioned, pipe ||9will still be open to atmosphere through the ahead pipe 5S if the engine is stopped from operation in the astern direction, or through therastern pipe 51 if the engine is stopped from operation in the ahead direction, so that with the engine stopped, as well as in restarting the engine in the direction in which it last operated which will'be presently described, the parts 'of the interlock valve device |58 'remain in the vposition in which they are shown in the drawing so that the maximum fuel limiting device |25 has no control over the fuel control shaft 3. The cam 34 kmoves the fuel con-V will then become effective in c 19 said operators control device for adjustment in unison with said control means.

3. An apparatus for controlling the supply of fuel to a prime mover comprising in combination, a fuel control member having a fuel control Zone of movement and being operable upon movement in one direction in said zone to increase the amount of fuel supplied to said prime mover and upon movement in the opposite direction in said zone to reduce rthe amount of fuel supplied to said prime mover, a prime mover operated speed governor comprising adjustable control means, and being operable to adjust said fuel control member to a position in said zone corresponding to the adjustment of said control means, adjustable stop means operable to prevent movement of said fuel control member in the direction to increase the supply of fuel to said prime mover in excess of the adjustment of said stop means, an operators control device, and means connecting both said control means and stop means to said control device for rendering said control device operable to vary simultaneously the adjustments of said control means and stop means.

4. An apparatus for controlling the supply of fuel to a prime mover comprising in combination,

a movable fuel control member adjustable to vary the amount of fuel supplied to said prime mover, a prime mover operated speed governor compris- Y ing adjustableV pressure means and operable to adjust said fuel control member to supply fuel to said prime mover in an amount proportional to the pressure of said pressure means, a control motor operable by fluid under pressure to vary the pressure of said pressure means in proportion to f the pressure of such fluid, a stop motor operable by fluid under pressure to limit movement of said fuel control member by said speed governor to increase the amount of fuel supplied to said prime mover to a degree substantially in proportion to the pressure of fluid in said stop motor, an operators control device for varying pressure of fluid,.and means connecting both said control motor and stop motor to said operators control device for rendering same effective to vary simultaneously the pressure of uid in both of said motors.

5..An apparatus forv controlling the supply of fuel to a prime mover comprising in combination, a movable fuel control member adjustable to vary the amount of fuel supplied to said prime mover, a prime mover operated speed governor comprising adjustable pressure means and operable to adjust said fuel control member to supply fuel to said prime mover in an amount proportional to the pressure of said pressure means, a control motor operable by fluid under pressure to vary the pressure of said pressure means in proportion to the pressure of such fluid, an operators control device operable to vary the pressure of fluid in said control motor, stop means adjustable by i uid under pressure to limit movement of said fuel control member to increase the fuel to said prime mover to a degree substantially in proportion to the pressure of such fluid, and means for subjecting said stop means to pressure of fluid supplied by said control device.

6. An apparatus for controlling the supply of fuel to a prime mover comprising in combination, a movable fuel control member adjustable to vary .r the amount of fuel supplied to said prime mover,

a prime mover operated speed governor comprising adjustable pressure means and operable to adjust said fuel control member to supply fuel to said prime mover in an amount proportional to the pressure of said pressure means, a control motor operable by fluid under pressure to vary the pressure of said pressure means in proportion to the pressure of such uid, anV operators control device operable to vary the pressure of fluid in said control motor, stop means Vadjustable to limit movement of said fuel control member in the direction to increase the amount of fuel supplied to said prime mover, and means operable by said motor to adjustsaid stop means substantially in accordance with the pressure of said pressure means.y

7. An apparatus for controlling the supply of fuel to a prime mover comprising in combination, a movable fuel control member for said prime mover having an idling position and being movable out of said idling position to increase the supply of fuel to said prime mover, a prime mover operated speed governor comprising a control spring operable to move said member in the direction out of idling position, and means driven by said prime mover and cooperative with said spring to position said member to supply fuel to said prime mover in an Vamount proportional to the force of said spring, an operators control device adjustable to vary the force of said spring, stop means adjustable to limit movement of said fuel control member out of idling position by said spring, andmeans controlled by said operators control device for adjusting said stop means to a position substantially corresponding to the adjustment of said operators control device.

8. An apparatus for controlling the supply of fuel to a reversible prime mover comprising in combination, a movable fuel control member having a fuel cut-off position and being movable out of said position to supply fuel to said prime mover in an amount proportional to thedegree of ysuch movement, a prime mover operated speed governor comprising pressuremeans operable to adjust said fuel control memberout of said cut-off position to a degree proportional to the force of said pressure means, cut-off means operableV to move said fuel control member to said cut-off position, an operators control device operable t0 adjust the pressure of said pressure means, means adapted to respond to operation of said control device, to adjust said pressure means, to simultaneously render said cut-off means ineffective, reversing means selectively conditionable to render said prime mover operable in either one direction or in the opposite direction, and mechanism controlled by the direction of operation of said prime mover comprising means operable upon operation of said prime mover in a direction, corresponding to the condition of said reversing means, to render said cut-off means controllable by said operators control device, and other means operableupon operation of said prime mover in a direction contrary to the condition of said reversing means to effect operation of said cut-off means to move said fuel control member to said cut-off position.

9. An apparatus for controlling the supply of fuel to a reversible prime mover comprising. in combination, a fuel control member having a fuel cut-off position and being movable out of start said prime mover in astern direction, means responsive to movement of said control device to said stop position to effect `movement of said fuel control member to said cut-offposition and being ineffective to control said fuel control member in said ahead and astern positions of said control device, fuel control means operable `to adjust said fuel control member out of said cut-olf position, fuel cut-off means operable to move said fuel control member to said cut-off position, an operators fuel control device, means for rendering said fuel control device eifective to simultaneously control operation of said fuel control means and to render said fuel cut-off means ineffective, and means including a device responsive to direction of operation of said prime mover operable upon movement of said maneuvering control device to a position contrary to the direction of operation of said prime mover to effect operation of said cut-off means to move said fuel control member to said cut-off position and operable upon starting of said prime mover in the direction corresponding to the position of said maneuvering control device to render said cut-off means responsive to operation of said operator-s fuel control device.

1U. An apparatus for controlling the supply of fuel to a prime mover comprising in combination, a movable fuel control member having a fuel cutoff position and being movable out of said cut-olf position to increase the supply of fuel to said prime mover in an amount proportional to the degree of such movement, a prime mover operated speed governor comprising an adjustable control element and being operable to adjust said member out of Said cut-off position to a degree corresponding tc the adjustment of said element, an operators control devi-ce operable to adjust said control element, stop means adjustable operation to limit movement of said fuel control member out of said cut-off position, means responsive to said operation of said control device to adjust said stop means, said stop means being also operable to effect movement of said control member to said cut-olf position, and means operable to effect operation of said stop means to move said fuel control member to said cut-off position.

1l. An apparatus for controlling the supply of. fuel to a reversible prime mover comprising in combination, av movable fuel control member having a fuel cut-oil' position and being movable out of said position to supply fuel to said engine in an amount proportional to the degree of such movement, a speed governor operated by said prime mover and comprising an adjustable control eleinent and being operable to adjust said member out of .said fuel cut-off position to a position corresponding to the adjustment of said element, an operators control device operable to adjust said element, stop means for said fuel control member, means controlled by operation of said control device, to adjust said element, to simultaneously adjust said stop means to limit movement of said fuel control member out of said out-off position to a degree corresponding substantially to the adjustment of said control element by said control device, said stop means being also operable to effect movement of said fuel control member to said fuel cut-off position, mechanism operable to effect operation of said prime mover in either one direction or in the opposite direction, directional means responsive to direction of operation of said prime mover, and means controlled by said directional means operable upon operation of said prime mover in thedirect'ion determined `bysaid mechanism to render said' stop means controllable bp said operators contro-l device and operable upon operation of said prime mover in a direction contrary to that determined yby said mechanism to effect operation of said stop means to move said fuelcontrol member to said cut-off position.

l2. An apparatus for controlling the supply of fuel toa reversible prime mover comprising in combination, a movable fuel control member having a fuel cut-off position and being movable out of said position to supply fuel to said engine in an amount proportional to the degree of such movement, a fluid motor operable by fluid under pressure to move said fuel control member in a direction away from said cut-off position to a degree proportional to the pressure of such fluid, stop means operable by fluid under pressure to limit movement of said fuel control member out of said cut-off position to a degree proportional to the pressure of the operating fluid and comprising means operable upon release of fluid under pressure to move said control member to said cut-off position, an operators fluid pressure regulating device, means adapted to connect both said fluid motor and stop means to said regulating device for rendering said regulating device effective to vary simultaneously the pressure of controlling fluid in said motor and stop means, valve means controlling the fluid control communication between said operators control device and stop means and operable to either open said communication or to close said communication and release fluid under pr ssure from said stop means, reversing means operable to condition said prime mover for operation in either one direction or in the opposite direction, and directional means responsive to direction of operation of said prime mover and operable upon operation thereof in a direction contrary to that determined by said mechanism to effect operation of said valve means to release fluid under pressure from said stop means and operable upon operation of said prime mover in a direction corresponding to the condition of said reversing means to effect operation of said valve means to open the communication control thereby.

13. An apparatus for controlling the supply of fuel to a reversible primeimover comprising in combination, a movable fuel control member having a fuel cut-off position and being movable out of said position to supply fuel to said engine in an amount proportional to the degree of such movement, a fluid motor operable by fluid under pressure to move said fuel control member in a direction away from said cut-olf position to supply fuel to a degree proportional to the pressure of such fluid, an operators control device arranged to control the pressure of uid in said motor, adjustable stop means for said fuel control member, means adjustable by said control device in synchronism with operation of said fluid motor to adjust said stop means to limit movement of said fuel control member out of said cut-oil position to a degree corresponding substantially to the pressure of fluid in said motor, structure for operating said stop means to move said control member to said cut-off position, re-

versing means operable to condition said prime` mover for operation in either one direction or in the opposite direction, directional means responsive to direction of operation of said prime of said reversing means to render said structure le of this patent:

effective to move said fuel control member to 5 said fuel cut-01T position and operable upon UNITED STATES PATENTS operation of said prime mover in the direction determined by said reversing means to renderV said stop means controllable by said operators control device. 10

ROY R. STEVENS.

Number Y Name o Date 2,413,390 Stevens Dec. 31, 1946 24 mover, and means controlled by said directional REFERENCES CITED means operable upon operation of said prime Y mover in a direction contrary to the condition The following references are of record in the 

